There are micropumps for the controlled and high-precision dispensing of insulin. It is believed that previous micropumps have been plagued, however, by complex manufacturing processes having many nonstandard process steps. The many special process steps according to the previous related art make micropumps of this type costly and lower the manufacturing yields.
In addition, other micropumps are believed to be insufficiently accurate with respect to the dispensed drug quantities. Micropumps for insulin dispensing must operate very accurately with high metering accuracy, however, and without complex sensors for detecting dispensed insulin quantities. Active flow measurement is very problematic in connection with insulin, because the material reacts adversely to elevated temperatures, for example, in connection with so-called hot film sensors for flow measurement.
In addition, the lack of reliability is a serious disadvantage of known micropumps: thus, for example, in micropumps according to the related art, the dispensed insulin quantity is a function of the initial pressure in the insulin supply container, which may be placed under pressure mechanically if it is designed as a flexible bag. For example, placing or laying the pump carrier on the insulin micropump may cause the supply container to unintentionally dispense insulin, or may result in an unintentional increase in the dose just dispensed. In view of the hazardousness of an insulin overdose, this is to be avoided under all circumstances.
A method for manufacturing a micropump is discussed in EP 1 651 867 B1. The manufacturing of the known micropump is extraordinarily complex, because during the production process, in which different silicon layers are structured from two opposing sides, fragile intermediate states arise again and again, for example, as shown in FIGS. 3b and 3c of the publication, which must be supported in a complex fashion in order to avoid permanent damage to the micropump already during its manufacturing.